Bring back the Sydney Rock Oyster

Inner West Council is throwing its support behind a program aimed at returning Sydney Rock Oysters to Sydney Harbour, and restoring a much-needed natural filter to Sydney’s waterways.

Council has been approached by the Sydney Institute of Marine Science (SIMS) and the Harding Miller Foundation regarding taking part in the Living Seawalls:Bring Back the Sydney Rock Oyster Project.

The Living Seawalls Project has developed tiles that can be attached to seawalls to create space and habitat for oysters and other plants and animals.

Inner West Mayor Darcy Byrne said that oysters could filter an astonishing amount of water naturally.

“One oyster can filter around 190 litres of water in a single day,” he said.

“Unfortunately since European settlement, oyster reefs, which covered the coastline, have been largely destroyed.

“At the time of colonisation, the oyster reefs were so large that ships had to sail around them.

“Now we have an opportunity to bring back the Sydney rock oyster and the comeback can start here in the Inner West,” said Mayor Byrne.

Colonists used oyster shells to help make the mortar that held together early buildings such as Vaucluse House and Hyde Park Barracks. By the 1860s most of the oyster reefs in New South Wales were decimated and today less than 1% of the original population remains.

Oysters are natural filter feeders – they feed by pumping water through their gills, trapping particles of food as well as nutrients, sediments and chemical contaminants.

Concrete and sandstone artificial seawalls, which encompass approximately 50% of Sydney Harbour’s shoreline, do not provide the rocky crevasses on which oysters depend for survival.

The seawall tiles have been proven to increase the survival of oysters and native biodiversity. They are installed to sit 10cm off the wall meaning that any existing marine life is protected, and both sides of the tiles can be colonised by oysters and other aquatic life.

The project group has identified sections of seawall within the Inner West Local Government Area on which they would like to pilot the system.

Council Officers are working to identify an easy way to navigate approval processes for the installation of the tiles.